Isolation of Potential Pathogenic Bacteria of Farmed Tilapia and Their Antibiotic Resistance Patterns in Selected Farms in Zambia

Abstract

Antibiotic resistance is a growing, global health problem affecting both humans and animals. The study utilized questionnaires directed at fish farmers to gather information on aquaculture practices and antibiotic use. Bacterial samples were collected from six different Tilapia farming sites in North and South Zambia. In total, samples were taken from 60 fish from the intestines, skin, and kidneys. These bacteria were identified using 16S sequencing and isolates of the genus Aeromonas were analyzed using the disk diffusion method to determine the pattern of antibiotic resistance among the bacteria. The highest occurrence of established resistance was observed against ampicillin and some degree of resistance to tetracycline. Additionally, a consistently lower zone diameter for erythromycin was recorded. Regarding the other antibiotics, there was a relatively large variation in zone diameter across the locations, but there are no clear guidelines for zone diameter from EUCAST or CLSI.